Strand manufacturers and everyone talk about what problems should be paid attention to in the use of steel strands?

　　(1) Storage:

　　The steel strand manufacturer said that the steel strand should be stored in a dry warehouse. The sleepers should be erected on the ground for outdoor storage. Direct contact with the damp ground is not allowed, and waterproof cloth or rain shelter should be covered to shorten the storage period as much as possible. Rust-proof packaging should be used when ordering under special circumstances. The surface rust of the steel strand will not affect its use, but visible "pinholes" will affect its mechanical properties.

　　(2) Hoisting:

　　The steel strand manufacturer reminds everyone that the hoisting of steel strands should be carried out in sequence, neatly stacked, and with gaps. Unbonded prestressing tendons should be hoisted parallel to the three hemp rope eyelets, and steel wire ropes should not be used for direct hoisting. Coiled steel strands should be lifted using forklifts or special lifting devices to prevent loose broken steel strips.

　　(3) Usage:

　　1. Any form of heating and deformation measures are strictly prohibited during the use of steel strands to avoid reducing the mechanical properties of steel strands.

　　2. Welding is strictly prohibited during use, because the strength of the weld is much lower than that of the steel itself, and the weld is easy to break wires during tensioning.

　　3. Steel strand cutting should use toothless presses (grinding wheels). Electric welding cutting is easy to damage the surface around the steel. At the same time, the local heating at the end will significantly reduce the performance.

　　4. When using cyclic reinforcement for prestressed steel wires, the bending radius shall not be less than 3 times the diameter of the steel wire.

　　5. Steel strands packaged in coilless coils should be released from the inner ring tap in a vertical state, and the drawn steel strands are spring-like and automatically straighten. Direction: The spiral direction of the spring after tapping is consistent with the twisting direction of the strand, otherwise it will twist or twist the wire.

　　6. The twisting direction of steel strands is generally left-handed. Right-handed twisting should be specified in the contract, otherwise it will directly affect the matching with the anchor.

　　7. The quality of the upsetting of prestressed steel wires is not directly related to the quality of the steel wires themselves, but excessive strength will be detrimental to the quality of the steel wire upsetting, so when you choose the upsetting anchor, you should explain it to our company in the order.

　　(4) Acceptance:

　　1. The acceptance of steel strands shall comply with relevant national standards, and the testing instruments shall be national statutory measuring instruments and comply with the provisions of the testing standards.

　　2. When there are quality problems in acceptance, attention should be paid to checking whether the following items meet the requirements:

　　(1) Whether the acceptance is carried out using new national standards and test methods.

　　(2) Whether the tonnage of the testing machine is appropriate; whether the measurement is accurate; whether the fracture surface of the steel is stuck; whether the strength is calculated using the nominal area.

　　(3) Whether the bending chuck of the bending testing machine conforms to national standards, and whether the surface finish, hole height, and test bending angle of the chuck conform to the standards.

　　(4) A sharp and standard marking distance tool should be used to measure the elongation of the steel, and the surface of the steel should not be damaged.

　　(5) Whether the steel itself has serious corrosion or artificial surface damage caused by storage.

　　(6) Wire laying: A wire laying machine should be used to lay the steel strands before use.